F-35 'incomparable' to Harrier jump jet, top test pilot tells El Reg

Naturally we demanded proof – and we got it

Interview What's it like to fly an F-35 fighter jet? We interviewed the chief British test pilot about a uniquely British flying technique – and then had a play with a full cockpit simulator to find out for ourselves.

Squadron Leader Andy Edgell is the Royal Air Force's top test pilot for the F-35 flight trials programme. A former Harrier pilot with sea time on two of the UK's previous aircraft carriers, Her Majesty's Ships Ark Royal and Illustrious, as well as operational deployments to Kandahar, Afghanistan, he is now based at the US Navy's test base at Patuxent River. He spoke to The Register in London yesterday at an F-35 press event.

In his view the F-35 and the Harrier, despite broadly doing the same thing (landing vertically) are "almost incomparable" in flying terms: "The design principle of the F-35 is 'low effort' while the Harrier is a challenge to fly."

Andy explained: "The human brain has a finite capacity and we don't want to use that on flying... we want to concentrate on being an operator of sensors."

The theory behind the F-35's "sensor fusion" concept is that by putting some of the world's most advanced radars and other sensors on it, and then networking those with other F-35s, the unparalleled situational awareness this gives the pilots makes them a far more formidable fighting unit than other current frontline fighter jets.

But does the high level of automation leave you "vulnerable" to the aircraft's whims while the pilot pores over his screens, we wondered? "You are in charge, if you choose to use it. Additional automation is there too – height, speed, heading hold. If you need to be hands-on with the throttle and stick, that's available. If you had a dynamic flight, you can dial that down."

SRVL – a thoroughly British bit of innovation

Andy also talked about the "uniquely British" manoeuvre that the UK team at Pax River developed, the shipborne rolling vertical landing (SRVL). For a jet fighter like the Harrier or the F-35, the normal landing technique on an aircraft carrier is to fly over the designated spot, hover and gently set down. But, as Andy explained, this reduces the amount of what he described as "Bernoulli lift" generated by the aircraft's wings. With less lift available, you reduce the maximum landing weight (too heavy and you break the undercarriage during the thump of touchdown) – and therefore the pilot may have to jettison expensive missiles and fuel to bring the aircraft back within safe vertical landing limits.

With the SRVL technique, however, the pilot combines the vertical landing and a traditional horizontal landing like you'd see at an airport. By doing this the amount of Bernoulli lift available is increased – and, in naval aviation terms, the number of unused missiles that can be brought home to fight again with is increased.

"It's a 35-knot overtaking speed at a seven-degree angle relative to the boat," Andy said. "You're literally coming down at the perfect speed and the perfect angle. This is British, utterly British," he enthused. "Everything we've done with the VAAC Harrier at places like Boscombe [Down, home of British military aviation research], stuff with modelling on how aircraft flies, it's brilliant."

"The VAAC Harrier developed this years ago, with landings on [French aircraft carrier] Charles de Gaulle and the principles behind it were invented by the British," said Andy. The VAAC (Vectored thrust Advanced Aircraft Control) system, developed over the 1980s and 1990s by the British aeronautical industry, was eventually incorporated in the production F-35B, as is being flown by the RAF, the Royal Navy, the US Marines and Italy.

That theme of automation also plays into the training for operating the F-35. According to both Andy and BAE Systems, the biggest sub-contractor on the F-35 project, around 3,000 hours of test flying have been completed on the full-motion simulator at BAE's Warton plant. Faith in the fidelity of the simulators is critical for the "flight" trials taking place in the UK, which includes both test flying and the training of landing signals officers (LSOs), who are F-35 pilots tasked with talking their comrades safely down to the deck. The simulators for both are linked, meaning the trainee pilot and trainee LSO can interact.

Andy praised the dedication of the BAE team working on the trials, joking: "Every time I see them I'll say, how's the marriage going?"